Apparatus for producing compounds of tin.



vaA'rEmm) JAN. so, 1906.

o. E. AGREE.' PRODUGI'NG COMPOUNDS OP TIN. .D JUNE s`.`19oa. Bmmwnn JUNE 22.1905.

APPARATUS Fi.

APPLICATION FIL 2 sums-sun; 1.

No.f810,897. PATENTED JAN.,30; 19.06. C. E. AJKER.

APPARATUS FOR PRODUGING COMPOUNDS OP TIN.

APPLUATION PIL-ED .TUNE 8. 1903. BENEWBD JU'NE 22.1905.

' 2 SHEETS-SHEET 2.

UNITED STATES PATENT OFFICE.

CHARLES E. ACKER, OF NIAGARA FALLS, NEW YORK, ASSIGNOR TO ACKER PROCESS COMPANY, A CORPORATION OF NEW JERSEY.

APPARVATUS FOR PRODUOING COMPOUNDS OF TIN.

Specification of Letters Patent.

Patented Jan. 30, 1906.

Application filed June 8,1903. Renewed June 22, 1905. Serial No. 266.507.

upon metallic tin with hydrochloric acid in solution, thereby forming stannous chlorid, and subsequently converting said stannous chlorid to stannic chlorid by addition of potassium chlorate to the acid solution. This process is relatively expensive, since the chlorin is derived from the comparatively costly compounds hydrochloric acid and potassium chlorate, and is furthermore subject to the disadvantages that the solutions produced cannot Vin practice exceed a density of 5()O to 51O Baume and are contaminated by the presence of considerable quantities of potassium chlorid derived from the reduction of the chlorate. Furthermore, it is impractical to concentrate such solutions', by reason of the loss of stannic chlorid by volatilization and the tendency of the solutions to become basic. Solutions of a density of O BaumeJ have been prepared by first producing a solution of stannous chlorid, concentrating the same to saturation, and subsequently convert-.

ing it, by means of potassium chlorate, to stannic chlorid; but this process is an expensive one, and the solutions obtained are also contaminated by potassium chlorid.

VI have discovered that stannic-chlorid solutions of high concentration and uncontaminated by impurities' of any kind may be produced by circulating a solvent containing chlorin successively and repeatedly in contact with metallic tin and in contactwith a reagent capable of converting the tin in solution from the divalent to the tetravalent state and have claimed such process in my cepending application, Serial No. 160, 564, led June 8, 1903. I have also discovered that if such stannic -fchlorid solutions having a specic gravity equal to or exceeding 1.800- be converted by contact with metallic tin to stannous-chlorid solutions of a corresponding concentration the stannous chlorid will separate from said solutions in the form of crystals of a high degree of purity. Such process I have claimed in my copending application, Serial No. 160,565, filed June 8, 1903.

The present invention is an apparatus which may be employed for carrying out either of the processes above referred to. i

For a full understanding of my invention reference is made to the accompanying drawings, wherein- Figure 1 shows in vertical section one form of apparatus which may be used for carrying out my. process. Fig. 2 is' a similar view showing a modified form thereof. Fig. 3 is a similar view of a further modification. Fig. 4 shows in vertical section a form of electrolytic cell which may serve as a source of chlorin or of a gaseous mixture containing chlorin.

p Referring t0 Fig. 1, 1 represents a vat or tank which may convenientlyl be of glazed earthenware. 2 is a storage-reservoir, and 3 a reaction tower, shown as of the -Rohrmann type, but which .may be of any desired character. Means, consisting pf a conduit 4 and an air-injection pipe 5, leading into the lower portion thereof, are provided for continuously or intermittently conveying the solution in the tank 1 to the storage-reservoir 2. From said reservoir the liquid is permitted to flow downwardly through tower 3 and to return thence by conduit 6 to the vat 1. The vat 1 contains, in addition to the liquid to be hereinafter described, a mass of metallic tin, preferably in a suitably-divided condition, and to maintain a body of clear liquid in the region ofthe inlet to the conduit 4 said conduit is surrounded by a protective casing 7 which is conveniently provided with apertures 8 at the lower end for the admission of the liquid.

lMy process depends upon the fact that'certain tin salts in which the tin vis in the tetravalent state are extremely energetic solvents for metallic tin, the metal passing into solutionv brought into contact with metallic tin and from the system at a point immediately fol lowing the treatment with chlorin. If the liquid contains an excess of chlorin, said excess is removed by the careful addition of stannous chlorid, and a clear, pure, colorless, and dense solution is obtained. To obtain a solution containing the tin in the divalent condition, it may be withdrawn from the systexnat a point immediately following the treatment with metallic tin, or, if desired, the solution may be withdrawn as stannic chlorid and subsequently subjected in a separate vessel to the action of metallic tin to convert it into stannous chlorid.v From solutions so produced the stannous chlorid will separate in the form of crystals of a high degree of purity, and if the stannous-chlorid solution is formed at a temperature above the normalsay at about 500 or 60o centigrade-a large yield of the crystals will be obtained when the solution is permitted to cool.

Fig. 2 shows a modified form of device in which the liquid after being subjected to the action of chlorin in the reaction-tower 3 is permitted to ilow into one of a seriesof pressure-tanks 1', a number of such tanks being provided and filled and discharged in succession, as will be readily understood. Said tanks -1 contain metallic tin, and after the solvent has been permitted to remain in contact therewith for a sufiicient time the tank is closed and air-pressure applied above the surface of the liquid by means of a pipe 5', the liquid beingthereby forced to the upper reservoir 2, from which it returns through the tower 3, as above described. It will be obvious that any suitable means for securing the circulation of the liquid may be substituted for` those described.

In Fig. 3 I have shown a further modification wherein an intermediate tank, tower, or

. the delivery of the same to the pressure-tank or other elevating device 1". ,17 is a cock for wlltlldrawlng the solution from the pressureta l d l nasa The construction of the-apparatus may be considerably varied without departure from my invention, the essential features being a dissolving-tank for metallic tin, a reactiontower in operative connection therewith, and means for producing a dilute gaseous mixture containing chlorin communicating with said reaction-tower. v

I have shown at 14 15 an inlet and outlet, respectively, for the gas which serves to convert the tin from its divalent to its tetravalent condition and have referred to this gas as chlorin. 1 have discovered, however, that it is neither necessary nor advisable to use pure chlorin gas for this purpose, but that the gas may contain a large proportion of air or oxygen. 1 have further discovered that the reaction is facilitated by the injection of steam into the chlorin, as by pipe 16, with the consequent formation of hydrochloric acid or by the use of hlorin containing a certain proportion of l hydrochloric acid.

I have employed a gaseous mixture containing ninety-live to'ninety-six per cent. of air, four to five per cent. chlorin, and a small percentage of hydrochloric acid. It will be understood that the reaction evolves a considerable amount of heat and that the temperature if uncontrolled would rise rapidly to a point y at which stannic chlorid would be volatilized. The useof dilute chlorin as described possesses the advantage that a portion of this heat is absorbed in raising the temperature of the large volume of gas so provided and that, therefore, it is possible to utilizelarger absolute quantities of chlorin in a given timethatis to say, one result of employing a dilute gas is to materially increase the output from a given apparatus.4 The addition of hydrochloric acid or the utilization of gases containing vhydrochloric acid results in the acceleration of the solvent action of stannic chlorid IOO upon metallic tin and serves also to prevent A the formation of oxychlorids of tin, the preserze of which may in some cases be undesira e.

It will be understood that the dilution of the chlorin need not be so great as above indicated byway of example and that proportionate eifects are secured by the use of smaller proportions of the diluent.

A gas possessing the general characteristics above referred to may be conveniently produced by the operation of my electrolytic cell, substantially as described in my prior patent, No. 674,691, issued May 21, 1901, and as illustrated in Fig. 4, in which two cells of this character are shown in operative connection with a common chlorin-flue 14.' Said cells comprise an iron frame or bed 18, lined interiorly with magnesia bricks 19. The cathode consists of a body of lead 20, which in operation is maintained in fusion and is circulated IIO beneath carbon anodes 22. 23 is a body of I dium passing to the lead cathode and the chlorin being conducted to the Hue 14 and thence to the reaction-tower. 'I he conduit 14,

above described as an inlet for the gas whichl serves to convert the tin from a divalent to a tetravalent state, may be, therefore, the outlet of an electrolytic cell in which chlorin is produced. suitable means being provided for insuring the dilution of the chlorin. In the construction illustrated the chlorin is diluted by means of air drawn into the cell by a suction fan operating in connection with the chlorin-'conduit 14 or outlet 15 and may also be diluted, if desired, by the introduction of steam at 16.

It will be obvious that the character of the original liquid, which under the conditions of my process is to become a solution of stannic chlorid, may be considerably varied. Thus water may be employed, or any desired proportion of stannic chlorid, stannous chlorid, hydrochloric acid, or stannous or stannic oxychlorid may be added thereto. In any case the result of the treatment by chlorin is to form a solvent for tin, and the result of the repeated utilization and regeneration of this solvent is to form solutions of stannic chlorid of a concentration heretofore unattainable. The result of the final conversion of stannicchlorid solutions thus produced to the divalent state is to form solutions of stannous chlorid of a concentration heretofore unattainable ina commercial way and from which the salt may be obtained in the form of crys tals of high purity.

The reaction proceeds with great facility at a temperature of O to 60o centigrade; but the process may be carried out at any temperature below the point at which stannic chlorid is volatilized. i

1. An apparatus for producing chlorin compounds of tin, comprising a dissolving vessel for effecting the solution of tin in a solvent vcontaining chlorin, a reactiontowcr, means for circulating the solution through said dissolving vessel and reaction-tower, means for producing a gaseous mixture containing chlorin and a diluent insufficient proportion to prevent undue rise of temperature, and means for delivering said mixture to said reactiontower, substantially as described.

2. An apparatus for producing chlorin compounds of tin, comprising a dissolving vessel for eectingthe solution of tin in a solvent containing chlorin, a reaction-tower, means for circulating the solution through said dissolving vessel and reaction-tower, means for producing a gaseous mixture containing chlorin and hydrochloric acid, and means for delivering said mixture to said reaction-tower, substantially as describedv 3. An apparatus for producing chlorin compounds of tin, comprising a dissolving vessel for effecting the solution of tin in a solvent containing chlorin, a reaction-tower, means for circulating the solution through said dissolving vessel and reaction-tower, means for producing a gaseous mixture containing chlorin, means for introducing steam into said mixture, and means for delivering said mixture to said reaction-tower, substantially as described.

4. An apparatus for producing chlorin compounds of tin, comprising a dissolving vessel for effecting the solution of tin in a solvent containing chlorin, a reaction-tower, means for circulating the solution through said dissolving vessel and reaction-tower, an electrolytic cell for the production of chlorin, means for diluting the chlorin produced by said cell, and means for delivering the diluted chlorin to said reaction tower, substantially as described.

In testimony whereof I ax my signature in presence of two witnesses.

A CHARLES E. ACKER. Witnesses:

J. H. SGHERMERHORN, D. S. MACKAY. 

